Trigger mechanism for firearms



April 19. 1921'. 1,625,768

C. H. BARNES `'IRIGGER MECHANISM FOR FIREARHS Filed April 25. v192:5

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CHARLES I-I. BARNES, OF ILION, NEWVYORK.

TRGGER MECHANISM FOR FIREARMS.

Application filed April 23,

This invention relates generally to tirearms and more particularly to that class oi' lirearms having a set trigger mechanism for discharging the saine.

A broad object ot the present invention is to provide a trigger mechanism ot' the type haring a main trigger and an auxiliary or set trigger pivoted on the main trigger which is reliable in operation, easily' operated, inexpensive to nianutacture and which may readily be attached to the tirearms now in use.

More speciiically it is an object of the present .invention to provide a trigger mech` anisin which normally requires lan appreciable movement ot the trigger to release the tiring member to discharge the arm, with an auxiliary 'trigger which may be readily and quit-lil y set to a position which will require a less degree ot movement and pressure of the set trigger to release the tiring member.

ln trigger mechanism olf the class ot lirearms just described the lull strain and compression o't the tiring-pin spring has been exerted against the pivoted sear and in order to preclude the possibility or' an accidental discharge oi the firearm a large amount ot bearing sui-tace has been provided between the cooking piece and the sear. This construction required a heavy pull as well as an appreciable movement ot the trigger in order to release the sear t'rom the rockin@Y piece. against the tull strain and compression ot the tiring-pin spring.

in certain kinds oli shooting it is desirable that the gun be, iii-ed by a comparatively light pressure upon the trigger thus precluding the possibility olf disturbing the ac curacyi ot aim while discharging the gun. ln orde to meet this requirement firearms are usually equipped with a second trigger known as a set or hair trigger.

lei-tain constructions of set triggers heretolore applied to lirearms required the intervention ot' a second trigger the pivotal point of which is separate and independent of the regular trigger and to so equip a lirearmv with this type ot set trigger usually required a reorganization ot parts and practically a reconstruction ot the trigger mechanism.

It is an object ot the present invention to provide a set trigge' insuch a torni that it can readilybe applied to firearms `now in general use in such a manner that the addi. tional parts required can be readily applied with little difliculty and require compara- 1923. Serial No. 634,082.

and showing the trigger mechanism cocked,`

for tiring the gun by a pull on the regular trigger. l

Fig. 2 is a view similar to Fig. 1 Ashowing the set trigger adjusted sol that the lirearm may be discharged by a relatively light pull.

Figl 3 is a top plan view ot the trigger trame showing the adjustable sear block and adjusting screw.

Fig. 4 is a view in perspective oli the ad-4 justable sear block showing the retaining spring in position. v

Fig. 5 is a plan view of the underside of the stock with the trigger guard removed showing the means for retaining the 'cylindrical spring housing' in place.

For the purpose of illustration the present invention is shown applied to that type ot' lirearm known asI the Springfield, model 1917, rifle which has been used quite extensively in military service and to this end I have shown in the drawings this particular type ot rifle. The trigger mechanism and associated jparts of this type of rifle is shown and explained in detail in the -patent to John D.. Pedersen #1,355,417,

Get. 2, 1920, and for further details of construction reference may be had to the said patent. It is to be distinctly understood that althougl'r this particular type of firearm Yhas been shown, it is'merely for the purpose of illustration and the inventive ideas are capable ot being einbodiedin and applicable .to firearms oi' other varieties.

As shown in Figs. land 2 the Spring- -ield rifle comprises a barrel secured to a receiver or `main frame 9, having therein a breeching chamber. Slidably mounted and operable in the main frame y9 is a reciprocable breech bolt 10. The stock llhas the Arm usual or'estock 12 and shoulder portions 13 (neither "of which are fully shown in t-he drawings.) The stock, frame and barrel are held assembled by the customary releasable astenings, one of which is shown as a screw 14 passing through a trigger fra/me 15, a bushing in the stock and into a threaded portion of the rear of the main frame 9. The magazine, the rear wall 26 of which is shown, holds the usual supply of cartridges which are fed into the breech chamber when 'the breech bo'lt is reciprocated in a manner which is well known in the art.

S'lfidably mounted in the breech bolt 10 is a firing bolt 151 the forward end of which is provided with the usual spring pressed firing pin '(not shown). The firing bolt- 151 is also provided with a downwardly extending cooking piece 16 which is adapted to abut against a sear nose 17 of asear lever 18 Which is shown pivoted at 19 to downward Vextensions of the receiver 9. A helica'l sear spring 201 interposed between the iframe 9 and one end of the sear lever 18 strongly actuates `the other end upwardly, its upward movement being limited by a transverse pin 46 abutting against the iframe so that the sear nose 17 will pass in iront ot the cooking piece when the firing bolt '1151 is 'drawn rearwardly by virtue of the retraction of the breech bolt 10 in the operation 'of Cooking 'the arm. `When the arm is cocked and the 'breech vbolt locked in tiring position the firing pin will be held back against the compression ot its spring by the 'engagement of the cooking piece 16 and the Sear nose 17. In order to effect disengagement oi' the sear nose and cooking piece to permit vthe firing ypin 'to move forwardly `there is provided a releasing trigger 20.

The trigger 20 is pivoted substantiallyv midway oit' the sear lever 18 by Aa transverse pin Z1 and passes through the stock 11 and za s101324 cut in the frame 15 provided with a trigger guard 25., 'the lower end of `the trigger Abeing formed with a curved tinger Apiece 22. The Aupper end of the trigger jis lprovided with a rearwardly extending cam portion 28 contacting with the lower ledge of the main frame 9.

Assuming that the .gun ris closed and Alocked with the trigger Q0 in theposition in which Tit is Vshown in Fig. 1, it is apparent Lthat Iwhen the trigger is pulled bach in the 'ordinary manner by the linger piece the -cam upon its upper edge will rock upon "the lower edge 'of the trame 9 compressing ithe sear spring 201120 the extent required for disengaging the sear nose 17 from the coclring piece I16 permitting the ifiring pin to spring A:forward under the influence oi its spring -to discharge the cartridge.

From the foregoing it is evident that in /order to Idischarge the Ygun an appreciable movement of Ithe trigger as well as a coninspection otl `siderable degree of pressure is required to ldisengage the sear nose from rocking piece. To permit firing of the gun by a comparatively light pressure upon the trigger a second or set trigger is provided.

The trigger is provided with a longitudinal slot 27 within which is pivoted by a transverse pin 28 a set trigger 29 having a curved finger piece the contour of which is substantially the same as the linger piece or the trigger 20. The set trigger is urged rearwardly 4to its normal or inoperative position by a helical spring` 30. rJl`he `torward part of the set trigger is equipped with a nose 31 provided with an engag'ii-ig hook and an adjusting screw Reference character '34 indicates a cylindrical spring housing in Vwhich is inserted a helical spring abutting against a plungn er 3G slidably mounted within the 'housing 34. The rearward end of the said housing is conoidal and engages a conical depression formed in the forward edge of the trigger 20.. The plunger 36 abuts against a wall 26 of the 'magazine in a similar manner. rl`he spring housing is inserted in a `slot 50 (Fig. 5) formed in 'thestoclt 11,the forward end of the housing being provided with a. iiange 51 abutting against a shoulder 59 formed at Vthe end o1 the slot A59. This 'limits the rearward movement 0i' the cylindrical housing 3l urged by the initial tension of the spring 35. will be seen ftroin 4an Fig. 1 that it' *trigger 20 "be actuated during a regular operation a separat-ion of the housing and 'trigger will occur and by providing this construction the conoidal end oit 'the housing will Ibe `held in proper alignment ior the reception of the conical depression when the `trigger is again cocked.

Pivoted within lthe ltrigger guard `trame 15 by a transverse pin 3i' is lan 'adjustable sear block 38 provided 'with la slot 39 through which project the triggers, and a )beveled nose l0 best lshown in Fig. el. In order to raise or lower the beveled nose l0 there is provided an kvadjusting screw l1 iornied with a head 58, the shank of the screw passing through `an open slot torined at the rear end of the seal.I vblock land through the trigger guard ytrame 15 in order to permitan exterior adjustment o-t -thesear block 38.` 4The purpose oi" adjusting the sea-r blodk will appear later. The adjustable lscar zblock is further equipped with a wire spring 42 so arranged as to be vn'iovable with the scar block 'and provided with a bent vhodk 213 adapted to hook over Athe nose 32 oi" the vset trigger when the latter has lbeen adj-usted to its set position.

Vfhen it is desired to operate the auxiliary or -set trigger for accurate shooting the rpro- -cedure is las follows. Pressure lis yapplied to the rear edge ot the yiin-ger 4p'iece'of *the trigger 2O and the two triggers moved forwardly until the hook 32, which has in the meantime engaged the hook 43'of the spring 42, has been urged upwardly far enough to clear the beveled nose il0, whereupon it snaps upwardly as shown in Fig. 2. 'While the trigger 2O has been moved forwardly a considerable amount of energy has been stored in the spring 35 the said spring tending to 'force the trigger rearwardly but being prevented by the engagement of the hook 32 and beveled nose l0. After the engagement of the'hook 32 and nose 40 the spring 35 will rock the trigger 20 rearwardly a slight amount sufficient to separate the set trigger 29 from the regular trigger 2O as shown in Fig. 2. It will be noted at this time that although the trigger 2O has been moved forwardly no movement of the sear lever 18 will take place the cam 23 being merely drawn downwardly away from the lower edge of the frame 9.

In order to discharge the gun a slight amount of pressure is applied to the finger piece of the set trigger sufficient to disengage the hook 32 and nose 40 whereupon the energy stored up in the spring 35 will move the trigger 2() quickly rearwardly, the cam 23 contacting with the edge of the frame 9 to force the sear lever 18 downwardly thereby disengaging the sear nose 17 from the cooking piece 16 to permit the firingl pin to move forward to fire the cartridge.

It is to be noted that a relatively small amount of movement of the set trigger is required to disengage the hook 32 from the nose 40 and the energy stored in the spring is sufficient to afford practically an instantaneous disengagement of the cocking piece and sear nose. In order to vary the amount of Contact between the beveled `nose 40, and the rear edge of thevhook 32the adjusting screw 33 is provided. If the screw 33 is backed downwardly from the position shown in Fig. 2 a greater area of bearing surface will be provided requiring a greater movement of the set trigger to fire the gun. The amount of bearing surface determines to a great extent the sensitiveness of the set trigger, and practically any degree may be obtained by means of the adjustment of the screw 33.

As has been set forth previously the sear block 38 is pivoted and adjustable to various positions and the reasons for providing this construction will now be set forth. As stated previously the main frame 9 of the rearm and the trigger guard frame 15 are set in the stock 11 which is properly recessed to receive these parts. In t-he fabrication of the stock the recesses and slots vary perceptibly in dimensions, allowing the parts to fit in the stock a greater or less amount deending upon the depth of the recesses.

hese variations will obviously affect the sensitiveness of the vset trigger and to compensate for these variations the sear block 38 is made yadjustable and when the components are in place and securely fastened the proper adjustment and position can be readily obtained by the adjustment screw Ll1. l/Vhen properly adjusted no further attention will-be required unless other variations or changes have set in after the proper adjustment has been determined. This is an important feature of the present invention as it allows set triggers to be applied to guns already in use or the process of manufacture without any change in the parts. Any variations in the recesses formed in the stock are readily compensated foi' and practically any degree of sensitiveness of the set trigger which is consistent with safety may be readily obtained at will.

lVhile the form of mechanism `herein shown and described is admirably adapted to fulfill the objects primarily stated it is to be understood that it is not intended to confine the invention to the one form of embodiment herein shown and described as it is susceptible of embodiment in various forms all coming within the scope of the claims which follow.

l/Vhat is claimed is: y

1. In a trigger mechanism for firearms, a 1 main trigger, a set trigger pivoted upon the main trigger, a cooking piece, a sear lever in engagement with the cooking piece, means under control of the main trigger for disengaging the said sear lever and cocking piece and spring impelled means under cont-rol of the set trigger for actuating the main trigger.

2. In a trigger mechanism for firearms, a main trigger, a set trigger pivoted upon the main trigger, a cooking piece, a scar lever in engagement with the cooking piece, means under control of the main trigger for disengaging the sai-d sear lever and cooking piece and spring impelled means, interposed between the main trigger and a stationary abutment, under control of the set trigger for actuating the main trigger.l

3. In a firearm, a manually actuated main trigger for effecting the firing of said fire"v1 arm, powermeans for actuating said main trigger comprising acompression spring interposed between said main trigger and a fixed abutment, and a second trigger for l controlling said power means.

4. In a trigger mechanism for firearms, a main trigger, a set trigger pivoted upon the main trigger, a spring interposed between the main trigger and a fixed abutment, means whereby adjustment of the said main trigger will store up energy in the said spring and a device for holding the set trigger in its adjusted position.

5. In a trigger mechanism for firearms, a main trigger, a set trigger pivoted upon the mainv trigger, a spring interposed between the main trigger and a fixed abutment, means wh-ereby adjustment of the said; main trigger will store up energy in the said spring, an. adjustable sear block, means for holding the set trigger in its adjusted position, said means comprising a hook integral with the set trigger engageable witlr the adjustable sear block. v.

6. In a trigger. mechanism for firearms, a, trigger frame, an adjustable sear block, mounted on the said trigoer frame, a main trigger, a set trigger carri-ed by the main trigger, a hook carried by the set trigger' adapted to engage with the adjustable sear block and means for regulating the bearing surface between the said hook and sear block.

7. In a trigger mechanism for firearms, a trigger frame, an. adjustable sear block mounted. on. the said trigger frame, a main trigger, a set trigger carried. by the main trigger., a hook carried bythe set trigger adapted to engage with the adjustable scar block, a. spring for holdingthe hook in envgagement with the sear block and separate and independent means for adjusting the said set trigger and adjustable searfblock.

8. In a trigger mechanism for firearms, a trigger frame, an adjustable sear block mounted on the said trigger frame, a main trigger, a set trigger adjustably carried by the main trigger, means for holding the set trigger in engagement with the sear block and spring impelled means for causing a separation of the set and main triggers after the setl trigger has been adjusted.

9. In a firearm, a stock provided with a recess, a main fram-e adapted to besecured in said recess, main and set triggers carried by the said frame, a sea-r block, means carried by the set trigger for engaging the scar block when in its adjusted position, and mechanism for `compensating for the variations inthe recess to obtain the proper relation between the said sear block and means.

l0. In a firearm, aA stool( provided with a recess, a trigger iframeadapted to be secured in the said recess, a main trigger, a set trigger carried by the main trigger,l a

sear block carriedJ by the trigger frame, means carried byl the set trigger for e11- gaging the set trigger with the sear block, and mechanism for compensating for the variations in the recess to obtain the proper relation between the saidl sear block and said means.

l1. In a firearm, a main trigger' formed with a depression, a spring-urged' housing having a eonoidal end normally enga-ging the said depression, and means insuring the proper alignment of the said depression and conoidal end when they become disengaged upon movement of the main trigger from its normal position.

l2. In a firearm, a main trigger formed with a depression, a spring-urged member having a conoidal' end rnormally engaging the said depression, and meansl insuring the proper alignment of the said depression and conoi'dal end' when they become disengaged upon movement of the main trigger from its norma-l` position.

113. In, a firearm, a` manually actuated main trigger for effecting the firing of said firearm, power means for actuating said main trigger comprising a, compression spring interposed between said= main trigger and a fixed abut-ment, and' a secondi` trigger carried' by the first mentioned trigger for controlling said power means.

14C. In a. firearm, in combination, a main trigger for controlling the firingy of said firearm, power means interposed between said main trigger anda fixed abutment, a second trigger carried by the main trigger and means adapted to cooperate with said second trigger for preventing said power means from moving said main trigger.

l5. In a firearm, in combination, a frame, a main trigger for controlling the firing oi said firearm, power means interposed between said main trigger and afix-ed abutment, a second trigger carried by the main trigger, and means mounted in said.' frame adapted to cooper-ate' with said second trigger for controllingsaid powervmeans.V

In witness whereof I have slgned my name this 19th day of April, 1923.

CHARLES H. BARNES. 

